The present disclosure relates to a medium processing device including a discharge tray on which a discharged sheet-shaped medium is stacked, and an image forming apparatus provided with the medium processing device.
In an image forming apparatus, such as a multifunctional peripheral and a printer, a sheet-shaped medium, such as a paper sheet, on which an image is formed is discharged on a discharge tray through a discharge port. Conventionally, the image forming apparatus has a function in which a plurality of sheets is set to one unit (one bundle), and when the plurality of units (the plurality of bundles) is printed collectively, the plurality of units is sorted for each unit (that is, for each sheets bundle).
For example, there is a technique such that when a bundle of stapled sheets is discharged on the discharge tray, a discharge speed of a discharge roller of a shift mechanism is controlled to vary a discharge speed of the bundle of stapled sheets discharged on the discharge tray and to displace a position of the bundle of stapled sheets staked on the discharge tray in the discharge direction. Alternatively, in a configuration that the sheet fed from the discharge port is post-processed on the sub-tray and then stored in the stack tray, there is another technique such that the sheets are divided into one sheet group which is conveyed to the stack tray and another sheet group which is collected in the sub-tray to displace the sheet groups in the width direction. There is still another technique such that the recording sheets discharged from the copying machine sequentially are aligned for each bundle of sheets.
A user takes out the mediums stacked on the stack tray for each medium bundle separately. Easiness of taking out of the medium bundles separately is dependent on a thickness of the medium bundle, for example. However, the above described techniques do not demonstrate a control considering easiness of taking out of the medium bundles separately.